Strongback system for joining a handle to a hammer head

ABSTRACT

A striking tool having a handle engaged in an eye in a head. uses a metal strongback unit engaged in a slot the handle to secure the handle in the eye of the head. The metal strongback unit has openings in a web that fits in the slot in the handle that allow wedges to be driven into the handle in a manner that both the handle end and the web of the strongback unit are spread. Metal of the strongback unit urges against an inside surface of the head in the eye to form a secure fit. In a preferred embodiment the strongback unit has metal sides that may extend below the head and provide metal surfaces for overstrike protection.

FIELD OF THE INVENTION

[0001] The present invention is in the area of hand-held striking tools,such as hammers, and pertains more specifically to the interface betweenhead and handle of a striking tool.

BACKGROUND OF THE INVENTION

[0002] Hand-held striking tools have been used for centuries by peoplein a variety of disciplines as leveraged devices to provide a strikingforce to accomplish a seemingly endless variety of tasks. For example, aclaw hammer allows a user doing carpentry work to deliver sufficientstriking force to drive a nail into wood. A claw hammer is also used forremoving a nail or ripping apart lumber using its claw. A sledge hammeris another common hand-held striking tool used to deliver sufficientstriking force for heavy work such as driving a stake, chisel, ordriving a wedge into masonry, stone, wood, or other hard materials.Another common hand-held striking tool is a ball peen hammer used todeliver sufficient striking force for shaping and fitting metal, and fordriving machine chisels, rivet sets, machine wedges, and other similartools.

[0003] As previously described, hand-held striking tools are commonlyused as third class levers to provide a striking force to accomplishtasks such as driving a nail into a piece of wood, bending or formingmetal, breaking a rock, and other similar tasks. Third class levers arelevers where a fulcrum, also referred to as a pivot point, is at one endof a bar or rod. A load to be overcome is an object creating resistanceat the opposite end of a bar or rod. The effort, or force, to be appliedto a third class lever is somewhere in between the fulcrum and load. Inthe case of a hand-held striking tool such as a claw hammer, the fulcrumis a wrist with the force being provided by the deceleration of themovement of a hammer handle (bar or rod) at the wrist. The load in thiscase is a resistance presented by a piece of wood into which the nail isbeing driven.

[0004] The head of the hand-held striking device is commonly asignificant distance from the fulcrum and moves faster than the movementbeing applied at a user's hand, which is near the fulcrum. The increasedspeed of the head multiplies the applied force with which a strikingdevice head strikes a nail or digs into the dirt. The longer a clawhammer's handle, for example, the faster the head and the greater theforce that strikes a nail and overcomes the resistance of the wood. Thisprinciple applies to all other hand held striking devices, and isintensified in long-handled striking devices such as a pickaxe, or anaxe.

[0005] Hand-held striking tools are also commonly used as first-classlevers to provide a lifting or prying force to accomplish a variety oftasks. For example, some hand-held striking devices are used to pullnails out of a piece of wood, tear apart pieces of wood or otherbuilding material, pry loose a large rock, lift a log, and the like.First-class levers are levers wherein the load to be overcome is at ornear one end of a rod or bar, the effort, or force is applied at or nearthe other end of the same rod or bar, and the fulcrum, or pivot, issomewhere along the rod or bar in between the applied force and load.

[0006] An example of a hand-held striking tool being used as afirst-class lever is a claw hammer being used to pull out nails, whereinthe load to be overcome is the wood causing friction against an embeddednail. Another example of a hand-held striking tool being used as afirst-class lever is a pickaxe being used to pry out a rock or tree rootembedded in dirt or rock, where the load to be overcome is the dirt orrock causing friction against an embedded rock or tree root. Whenever ahand-held striking tool is used as a first-class lever, the force isapplied at one end of a long handle. The fulcrum is typically near theother end of the handle that holds the head.

[0007] The load for a hand-held striking tool being used as afirst-class lever, such as in a claw hammer or a pickaxe, is typicallyvery close to the fulcrum. Whereas the force for a hand-held strikingtool being used as a third-class lever is typically relatively far awayfrom the fulcrum. During prying or pulling tasks, the load applied istherefore moved less distance than the hand, which is at the oppositeend of the lever, and applying the force. This multiplies the force inwhich the claw hammer head pulls against a nail, or a pickaxe pullsagainst a rock.

[0008] The weakest part of a hand-held striking device is the interfacebetween the handle and the head. The conventional methods of interfacinga striking device head and handle, which are typically made of distinctmaterials, such as metal and wood, allows striking and pulling stressesto promote head-to-handle loosening, damage, and separation. Forexample, the impact force at the head of a claw hammer, being used as athird-class lever against a nail, is often as high as 300 pounds.Because of the greater length of its handle and greater weight of itshead, the striking force of the head of a pickaxe against the earth ismany times greater.

[0009] The bending moment applied at the head-to-handle interface of aclaw hammer been used as a first-class lever to pull a nail is often ashigh as 1000 foot-pounds. The bending moment levied against thehead-to-handle interface of a pickaxe pulling heavy rocks away from theearth is typically several times more.

[0010] The effect of these forces is exacerbated when a useroccasionally misses the target for which the strike is intended andstrikes a hard object, such as the edge of a piece of wood or a rock, atthe head-to-handle interface just below the head, causing further damageand weakening a head-to-handle interface.

[0011] Because of the inherent weakness in conventional head-to-handleinterfaces, it is this point that most failures in hand-held strikingdevices occur. Methods have been devised to make head-to-handleinterface configurations capable of withstanding impacts and pullingstresses described above without damage. These methods include using ahandle made with a material, such as high-impact plastic or heavy-gaugerolled steel that has particularly high strength and resiliency towithstand extremely high impacts and pulling stress. These types ofhandles are typically encapsulated in a resilient material, such asnatural or synthetic rubber, leather, or plastic, to provide someprotection from the shock from impact and to give a user a good grip onthe handle. Many users of hand-held striking devices, however, stillprefer the look and feel of wooden handles.

[0012] As stated above, a problem with many conventional methods forincreasing handle strength on hand-held striking devices is the inherentweakness in the design of interfaces. Current interfaces for hand-heldstriking tools typically comprise a handle whose end is shaped to make atight fit through a shaped opening, or eye, in the head. Such a shapedopening is often tapered to be larger at the end of the opening oppositethe side where the handle enters the head. Typically metal or woodenwedges are driven into the end of the handle to expand the handle intothe eye of the head to attain a tight fit. A tight fit, however, doeslittle to increase the strength of the conventional head-handleinterface.

[0013] Another common method for securing conventional head-to-handleinterfaces is by placing a bonding material, such as an epoxy adhesive,between the inner surface of the opening in the head and outer surfaceof the interface and of the handle.

[0014] The types of head-to-handle interfaces and methods of securingdescribed above are commonly used on all types of hand-held strikingtools, such as axes, sledge hammers, pickaxes, and the like. A problemwith these conventional solutions is that the striking and pullingforces are concentrated over a short distance at the interface. Theintensified stress at this small area is the cause of most hand-heldstriking tool failures. Head-to-handle interfaces made according toconventional art, regardless of the material of the handle or method ofsecuring it to the head opening, often fail because of this concentratedstress.

[0015] What is clearly needed is an improved method and apparatus forsecuring the head of a striking tool to its handle, providing both adurable, long-lived head-to-handle interface and an integrated system ofoverstrike protection to the handle. Such a method and apparatus, in apreferred embodiment, overcomes an inherent weakness in conventionalhead-to-handle interface methods while preventing damage to the handlecaused when a user misses a target and inadvertently strikes the handleagainst a hard object, damage that causes further weakness inconventional head-to-handle interface methods.

SUMMARY OF THE INVENTION

[0016] In a preferred embodiment of the present invention, for astriking tool having a plane of substantial symmetry and a head with aneye for engaging a portion of a handle, a method for securing the handleto the head is provided, comprising the steps of (a) slotting theportion of the handle that extends into the eye of the head in the planeof substantial symmetry, providing a slot with a first width; (b)engaging a metal strongback unit in the slot, the strongback unit havinga web with a thickness substantially the width of the slot; (c) engagingthe handle and strongback assembly into the eye, and (d) spreading theweb of the strongback unit until metal of the strongback unit urgesagainst an inside surface of the head in the eye.

[0017] In a preferred embodiment the web has at least one opening at anupper edge for a spreading wedge, and the web is spread in assembly bydriving a wedge into the handle and the opening in the web. Thestrongback unit may also comprise side elements having a second widthgreater than the web width, such that the side elements lie alongopposite sides of the handle with the strongback unit engaged in thehandle slot. Spreading the web urges the side elements against theinside surface of the head in the eye. Also in a preferred embodimentthe side elements are shaped to fit a curvature of the inside surface ofthe head in the eye. In some cases the handle is formed on oppositesides of the slotted portion to accommodate the side elements of thestrongback unit.

[0018] In another preferred embodiment the slot extends further along alength of the handle than the portion of the handle that extends intothe eye of the head, and the strongback unit fills the slot, such thatthe side elements, with the handle and strongback engaged, provide anoverstrike surface along a portion of the handle length below the head.In this embodiment as well, the handle may be formed along oppositesides along the slot edges to accommodate the side elements.

[0019] In still another preferred embodiment the strongback unit has afirst web in an upper portion having a length equal to the handleportion extending into the eye, and a second web in a lower portion, thesecond web formed at a right angle to the first web, and wherein thehandle is slotted with first and second slots at right angles toaccommodate both webs. In this embodiment the second web comprisesthreaded holes, and an overstrike plate is assembled to the handle belowthe head on the side of the handle toward a striking surface of thehead, the overstrike plate secured to the handle by fasteners extendingthrough holes in the plate and the handle, and engaging the threadedholes in the lower web.

[0020] In another aspect of the invention a striking tool having a planeof substantial symmetry is provided, comprising a head with an eye forengaging a portion of a handle; a handle with a slot of a first width inthe plane of substantial symmetry along a length of the portion of thehandle extending into the eye; and a metal strongback unit in the slot,the strongback unit having a web with a thickness substantially thewidth of the slot. The striking tool is characterized in that thestrongback unit is spread in the eye, urging metal of the strongbackunit against inside surface of the head in the eye, to secure the headon the handle. In preferred embodiments the web has at least one openingat an upper edge for a spreading wedge, and the web is spread inassembly by driving a wedge into the handle and the opening in the web.

[0021] In some embodiments the strongback unit comprises side elementshaving a second width greater than the web width, such that the sideelements lie along opposite sides of the handle with the strongback unitengaged in the handle slot. Spreading the web urges the side elementsagainst the inside surface of the head in the eye. The side elements maybe shaped to fit a curvature of the inside surface of the head in theeye. Also, the handle may be formed on opposite sides of the slottedportion to accommodate the side elements of the strongback unit.

[0022] In another embodiment the slot extends further along a length ofthe handle than the portion of the handle that extends into the eye ofthe head, and the strongback unit fills the slot, such that the sideelements, with the handle and strongback engaged, provide an overstrikesurface along a portion of the handle length below the head. The handlemay be formed along opposite sides along the slot edges to accommodatethe side elements.

[0023] In yet another preferred embodiment the strongback unit has afirst web in an upper portion having a length equal to the handleportion extending into the eye, and a second web in a lower portion, thesecond web formed at a right angle to the first web, and wherein thehandle is slotted with first and second slots at right angles toaccommodate both webs. The second web may comprise threaded holes, andan overstrike plate may be assembled to the handle below the head on theside of the handle toward a striking surface of the head, the overstrikeplate secured to the handle by fasteners extending through holes in theplate and the handle, and engaging the threaded holes in the lower web.

[0024] In various embodiments of the present invention described inenabling detail below, an improved apparatus and method is provided forsecuring handles to heads of striking tools.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1a is a side view of a metal strongback according toembodiment of the present convention.

[0026]FIG. 1b is a top view of the strongback of FIG. 1a.

[0027]FIG. 2a is a broken view of a conventional hammer head to be usedwith the strongback of FIG. 1a.

[0028]FIG. 3a is a side view of the end of a hammer handle usedaccording to an embodiment of the present invention.

[0029]FIG. 3b is a view of the handle section of FIG. 3a, rotated 90degrees.

[0030]FIG. 3c is a top view of the handle section of FIG. 3a.

[0031]FIG. 4a is a side view of the metal strongback of FIG. 1a, thehammer head of FIG. 2a and the hammer handle of FIG. 3a assembledaccording to an embodiment of present invention, but not secured.

[0032]FIG. 4b is a side view of the assembled components of FIG. 4asecured together according to embodiment of the present invention.

[0033]FIG. 4c is a top view of the assembled components of FIG. 4b.

[0034]FIG. 5a is a three-dimensional view of a strongback according toan alternative embodiment of the present invention.

[0035]FIG. 5b is a top view of a hammer handle fashioned to be used withthe strongback of FIG. 5a.

[0036]FIG. 5c is a side view of the strongback of FIG. 5a, the hammerhandle of FIG. 5b and the hammer head of FIG. 2 assembled according toan alternative embodiment of the present invention.

[0037]FIG. 6 is a simplified view of a metal strongback according toanother alternative embodiment of the present invention assembled with aconventional hammer head.

[0038]FIG. 7a is side view of a hammer handle and fastening elementsaccording to an alternative embodiment of the present invention.

[0039]FIG. 7b is a view at 90 degrees to the view of FIG. 7a.

[0040]FIG. 7c is an assembly view showing a hammer head assembled to ahammer using the elements of FIGS. 7a and 7 b.

[0041]FIG. 8a is a side view showing an apparatus in an alternativeembodiment of the present invention.

[0042]FIG. 8b is a side view of the apparatus of FIG. 8a showing theassembly completed.

[0043]FIG. 9a is an elevation view of yet another strongback accordingto an embodiment of the present invention.

[0044]FIG. 9b is a top view of a hammer head with the strongback of FIG.9a used to enhance joining a handle to the head.

[0045]FIG. 9c is a side elevation view illustrating the head and handlefrom FIG. 9b in assembly.

[0046]FIG. 10a is a side view of still another strongback according to apreferred embodiment of the present invention.

[0047]FIG. 10b is a top view showing the strongback of FIG. 10aassembled with a handle into the eye of a hammer head.

[0048]FIG. 10c is head, handle, and fastening components in a side viewfor the embodiment described relative to FIG. 10b.

[0049]FIG. 11a is a side view of a special wedge used in an embodimentof the present invention.

[0050]FIG. 11b is a top view of a handle, head and interface components,illustrating use of the wedge of FIG. 11a.

[0051]FIG. 11c is an assembly view illustrating assembly of thecomponents from FIGS. 11a and 11 b.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052]FIG. 1a is a side view of a metal strongback according to apreferred embodiment of the present convention. Strongback 101 comprisesmetal having relatively malleable or bendable properties, with a side103 and side 104 positioned on opposite edges of a web 102, providing ashape similar to a miniature I-beam. Sides 103 and 104 in thisembodiment have outer surfaces about half-spherical in shape with innersurfaces being flat. In alternative embodiments however, the shape ofouter and inner surfaces can vary greatly. Web 102 is provided having aheight D2 being approximately twice or more that of the depth of the eyeof a conventional hammer head, and a width D3 approximately equal tothat of a conventional hammer handle. Hole 106, passing completelythrough Strongback 101 is provided as a means to accommodate a standardfastening device such as a threaded bolt set. Slotted openings 105 areprovided in this embodiment as V-shaped notches cut, milled or fashionedby some other means to a depth D1 into the top edge of Strongback 101.

[0053]FIG. 1b is a top view of Strongback 101 of FIG. 1a. Thehalf-cylindrical shape of Sides 103 and 104 can be seen in this view,Sides 103 and 104 each having a width of D5. The thickness of Web 102can also be seen in this view.

[0054]FIG. 2a is a broken view of a conventional hammer head to be usedaccording to an embodiment of the present invention. Hammer head 201 hasan eye 203 having a width D3 at the bottom, essentially the samedimension as D3 in FIG. 1a, and a width D4 at the top, width D4 beingsomewhat larger than width D3. The varying dimensions create an openingsomewhat larger in cross-sectional area at the top of Eye 203 than atthe bottom, so that, in the process of attachment, when the top end ofan inserted hammer handle is spread to dimension D4, the hammer head isheld firmly in place.

[0055]FIG. 3a is a side view of the end of a hammer handle fashioned tojoin to a head using a strongback according to a preferred embodiment ofthe present invention. Handle 301 is provided having shoulders 302milled, cut or fashioned by some other means into each of two Sides 303to a depth of D5 equal to that of Sides 103 and 104 of Strongback 101 ofFIG. 1b. The upper portion of Handle 301 above Shoulders 302 is shavedor milled to a width of D3 and a height of D2, a height equal to that ofthe overall height of Strongback 101 of FIG. 1a.

[0056]FIG. 3b is a side view of the handle section of FIG. 3a. Slot 304is shown in this view as cut, milled or fashioned by some other meansinto the center of Handle 301 to a depth of D2 and having a widthsubstantially equal to that of Web 102 of Strongback 101 FIG. 1a.

[0057]FIG. 3c is a top view of the handle section of FIG. 3a showing thecutouts of shoulders 302 being of width D5, and slot 304 extendingcompletely through the upper portion of Handle 301. It will be apparentin this view that the overall shape of Strongback 101, as seen in thetop view of FIG. 1b, matches exactly the shape created by the fashioningof shoulders 302 and slot 304 into Handle 301, thus allowing for a closefit when Strongback 101 is inserted down into the top of Handle 301.

[0058]FIG. 4a is a side view of the metal strongback of FIG. 1a, thehammer head of FIG. 2a and the hammer handle of FIG. 3a assembledaccording to an embodiment of present invention. The purpose of thisview is to show how the components described above are assembledtogether previous to the final securing of the assembled Handle 301 andStrongback 101 to hammer head 201 according to this embodiment of thepresent invention. In this view Strongback 101 shown in FIG. 1a is showninserted down into the slotted top portion of Handle 301, the bottomedge of Strongback 101 seated upon shoulders 302 and the bottom edge ofslot 304, and attached using a fastener 402. Fastener 402 in thisembodiment is a standard threaded bolt with a hexagonal cap secured by astandard threaded nut at the opposite end. In alternative embodimentshowever, the type of fastener used in attaching Strongback 101 to Handle301 can vary. The assembled Strongback 101 and Handle 301 are theninserted up through the eye of hammer head 201 until the top edge ofStrongback 101 is flush with the top edge of hammer head 201.

[0059]FIG. 4b is a side view of the assembled components of FIG. 4asecured together according to embodiment of the present invention. Inthis view the assembly of the components of FIG. 4a can be seen with theaddition of wedges 401 which have been driven down into the open end ofthe handle and into slotted openings 105. The outward force created bythis action causes both the outer sides of the metal Strongback 101, aswell as the upper portion of wooden Handle 301 to spread outward towidth D4 and urge against the metal inner walls of the eye of hammerhead 201 accomplishing metal-to-metal contact. Because height D2 ofStrongback 101 is approximately twice that of the height of Hammer head201, and width D3 is smaller than width D4, the spread upper portions ofSides 103 and 104 of Strongback 101 secure hammer head 201 to theassembled Strongback 101 and handle 301, thus preventing Hammer head 201from slipping off. The lower portions of metal sides 103 and 104 thatnow protrude downward from the bottom edge of hammer head 201 along thefront and back edges of handle 301 also provide overstrike metalsurfaces giving overstrike protection to the upper portion of handle301. The overstrike surfaces prevent damage to wooden handle 301 in theevent of a user missing the target for which the strike of the hammer isintended.

[0060]FIG. 5a is a three-dimensional view of a strongback according toan alternative embodiment of the present invention. Strongback 501 isprovided having an upper portion 502 similar in shape, function andcomposition to that of Strongback 101 of FIG. 1a, but with a heightequal to that of the eye of a conventional hammer head. Lower portion503 is a web portion rotated 90 degrees in relation to upper Portion502. Lower Portion 503 can be fabricated and attached to upper Portion502 by brazing, welding or by some other means, or as an integral partof Strongback 501, twisted or bent 90 degrees. Threaded Holes 504 areprovided in this embodiment as means for an alternate method ofattachment to a handle such as Handle 301 of FIG. 4b. In otheralternative embodiments the number of Holes 504 can vary, as can theshape, location or size.

[0061]FIG. 5b is a top view of a hammer handle fashioned to be used withthe strongback of FIG. 5a. Handle 301 is shown in this view to have aslot 304 and shoulders 302 as in FIG. 3c but with a cross slot 505provided to accommodate lower Portion 503 of Strongback 501 wheninserted down into Handle 301. To allow accommodation of Strongback 501,cross slot 505 is cut, milled or otherwise fashioned into Handle 301 toa depth equal to the overall height of Strongback 501 allowing for thecomplete insertion of Strongback 501 into handle 301.

[0062]FIG. 5c is a side view of Strongback 501 of FIG. 5a, Handle 301 ofFIG. 5b and hammer head 201 of FIG. 2 assembled together according to analternative embodiment of the present invention. Wedges 401 are shownforcibly inserted and spreading the sides of Strongback 501 as in FIG.4b. Metal Caps 506 and 507 are provided in this embodiment to provideprotection to handle 301. Although no detail is given in this view, itcan be assumed Caps 506 and 507 have holes drilled or bored completelythrough, as well as holes drilled or bored completely through Handle301, holes positioned to coincide with the location of holes 504 ofStrongback 501, thus allowing accommodation of fasteners 508. Fasteners508 in this embodiment can be standard threaded bolts inserted throughthe holes of cap 506 or 507, through the holes of handle 301 andfastened by screwing the threaded end of fastener 508 into acorresponding threaded hole in portion 503 of strongback 501. Inalternative embodiments the fasteners used can vary greatly in form ornumber, as can the location of holes through which they pass and themethod of securing the fasteners once inserted.

[0063]FIG. 6 is a simplified view of a metal strongback according toanother alternative embodiment of the present invention assembled with aconventional hammer head. Many details have been omitted from this viewin order to provide a clearer view of the subject matter of thisembodiment. Strongback 601 is provided being similar in size and shapeto Strongback 101 of FIG. 1a, but with the addition of Shoulders 602located on opposite ends to provide an interface with, and support tothe bottom edge of a conventional hammer head as shown. In anotheralternative embodiment a strongback similar to that of FIG. 1a but witha shorter height that is equal to that of the eye of a Hammer head 201may be used. In this embodiment, because of the shorter height,overstrike protection is not provided nor is a hole such as hole 106, ora fastener such as Fastener 402. The method of securing a hammer head toa handle in this embodiment is accomplished solely by the insertion ofwedges as in FIG. 4b, thereby spreading the top portion of metalStrongback 601 against the metal surface of the eye of a hammer headsimilarly to methods previously described.

[0064]FIG. 7a is a broken side view of a strongback system with hammerhandle according to another alternative embodiment of the presentinvention. Metal Plates 703 and 704 are provided in this embodimentbeing equal to each other in size and shape, and having Holes 708 and710 passing completely through the bottom portion, holes through which afastener such as Fastener 706 can pass. Fastener 706 in this embodimentis a standard 2-piece assembly comprising of a threaded bolt as a firstpiece that is inserted and screwed into the female threaded hole of acylindrically shaped second piece at the opposite end of the assembly.The type of fastener used however can vary greatly in other alternativeembodiments. For example, a standard nut and bolt commonly known in theart could be used, as could a screw or some other similar fasteningdevice.

[0065] Hammer Handle 711 is provided in this embodiment as similar inoutward shape and appearance to that of Handle 301 of FIG. 3a, but withsome distinct differences. Handle 711 has a Hole 709 passing completelythrough Handle 711 and having a diameter sufficient to accommodate afastener such as Fastener 706. Hole 709 can also have varying diametersand other properties to accommodate different types of fasteners inother alternative embodiments of the present invention. A V-shaped Slot713 can be seen in this view cut into the upper portion of Handle 711.The purpose of Slot 713 in this embodiment is to accommodate a securingwedge used when attaching a hammerhead, and is described and depictedbelow in greater detail.

[0066]FIG. 7b is a broken front view of the hammer handle of FIG. 7a. Inthis view the width and orientation of notch 713 can be seen moreclearly, as can the centered location of Hole 709. Surface 717 isprovided having a surface area roughly equal to the dimensions of thebottom surface of Plate 703 so as to provide an even and flat surface onwhich Plate 703 will rest when secured. Although it is not shown in thisview a surface identical to Surface 717 is provided at the opposite sideof Handle 711 to accommodate the placement and securing of Plate 704.

[0067]FIG. 7c is a broken side view of the components of FIG. 7a securedto a conventional hammerhead according to an embodiment of the presentinvention. Plates 703 and 704 attach to Handle 711 using Fastener 706inserted through holes previously described. The assembly describedabove is then inserted up through the eye opening of a conventionalhammerhead such as Hammerhead 723 as shown. Wedge 720 is provided inthis embodiment to complete securing the assembled components describedabove. Wedge 720 is urged down into Slot 713 until fully seated and thetop edge of Wedge 720 is flush with the top edges of the assembledhandle 711 and hammerhead 723. The shape and diameter of wedge 720,being similar to that of Slot 713 provides a snug fit once inserted. AsWedge 720 is driven down into Notch 715, the angled sides of Wedge 720,wider at the top edge than at the bottom edge, make contact with theinner edges of Plates 703 and 704 driving them in an outward directioncausing the outer edges of Plates 703 and 704 to urge against the innerwalls of the eye of hammerhead 723, thereby securing hammerhead 723 tothe remaining assembled components. In some embodiments spot-welds maybe used at points 725 to secure each end of fully inserted wedge 720 tothe inner edges of plates 703 and 704, plates 703 and 704 being held inthe forced outward position.

[0068]FIG. 8a is a broken side view of a hammerhead and handle as usedwith a strongback and securing wedge according to another alternativeembodiment of the present invention. In this simplified view metalplates 805 and 806 are provided being similar in size and positionedaccording to the embodiment represented in FIG. 7c, but having notches809 cut, forged or fashioned by some other means into the inner sidesnear the top of each plate. Metal plates 805 and 806 are fastened toHandle 711 and the assembly is then inserted up into hammerhead 723,similarly to the components of FIG. 7c, until flush with the top edge ofhammerhead 723. Wedge 801 is provided in this alternative embodimentbeing similar in size in shape to Wedge 720 of FIG. 7c but withprotrusions 802 positioned on each opposite end of wedge 801 and havingouter dimensions similar to the inner dimensions of notches 809 ofplates 805 and 806.

[0069] Once the assembled handle 711 and Plates 805 and 806 are fullyinserted up into hammerhead 723, wedge 801 is inserted down, in thedirection shown, into slot 713 until fully seated, similarly to wedge720 of FIG. 7c. During downward insertion of wedge 801 the inner edgesof plates 805 and 806 are urged outward by the force of the angled sidesof wedge 801, urging the outer edges of plates 805 and 806 against theinner walls of hammerhead 723 as in FIG. 7c.

[0070]FIG. 8b is a broken side view of the components of FIG. 8aassembled according to an embodiment of the present invention. Wedge 801is shown in this view fully inserted into slot 713. Once wedge 801 isfully inserted, protrusions 802 fill the void created by notches 809 andsnap securely into place by the resilient tendency of plates 805 and 806to remain in the unforced inward position. With wedge 801 in the lockedposition, the outer edges of plates 805 and 806 are forced against theinner walls of hammerhead 723 thereby securing the components togetheras in FIG. 7c, but also allowing a user to remove or replace wedge 801if required.

[0071]FIG. 9a is a side view of a strongback according to anotheralternative embodiment of the present invention. Strongback 901 isprovided in this embodiment being somewhat similar in size and shape toStrongback 101 of FIG. 1a but having several distinct differences. Asingular notch 903 is provided in this embodiment to accommodate theinsertion of a securing wedge shown later in greater detail. Notch 903also has a vertical dimension similar to that of dimension D1 of FIG.1a, but has a shape more rectangular in nature. An enlarged circularopening is positioned at the bottom of notch 903 allowing for easierinsertion and less resistance when a securing wedge is inserted. Sides905 and 906 are provided in this embodiment being positioned on theouter edges of strongback 901 but having curved inner edges instead ofthe flat inner edges of strongback 101, thereby increasing the strengthof the interface between the web and sides when the outward forces arecreated by the insertion of a securing wedge. Serrations 908 are cut,welded or fashioned by some other means into the top outer edges ofsides 905 and 906 providing an improved hold on the inner walls of theeye of a hammerhead once a wedge is inserted. Hole 909, similar in sizeand position to hole 106 of FIG. 1a, is provided in this embodiment toallow for the use of a fastening device.

[0072]FIG. 9b is a broken top view of the strongback of FIG. 9a,assembled with a hammerhead and handle according to an embodiment of thepresent invention. This view shows strongback 901 assembled with ahandle 914 and a hammerhead 723 prior to insertion of a wedge. Handle914 is provided in this embodiment with a slot 916 cut across the centerinto the top to a depth approximately equal to that of dimension D1 ofFIG. 1a. This dimension however, can vary in different embodiments. Thepurpose of slot 916 is to accommodate a securing wedge similar topreviously described. The rounded shape of sides 905 and 906 can beclearly seen in this view.

[0073]FIG. 9c is a broken section view of the assembled components ofFIG. 9b with a securing wedge and fastener according to an embodiment ofthe present invention. A section view taken along line A-A of FIG. 9bshows greater detail of the components as assembled according to thisembodiment. Wedge 918 is provided that, when driven down in thedirection indicated into Slot 903, creates an outward force causing thesides of strongback 901 to urge against the inner walls of the eye ofhammerhead 723, thereby securing the components together similarly tomethods previously described, with serrations 908 enhancing the grip. Insome embodiments matching serrations may be provided on the innersurface oft the eye of the hammerhead. Fastener 920 in this embodimentis a standard nut and bolt but can vary greatly in other alternativeembodiments.

[0074]FIG. 10a is a side view of a strongback according to anotheralternative embodiment of the present invention. Strongback 11 isprovided in this embodiment being somewhat similar in size and shape tostrongback 901 of FIG. 10a but having a singular notch 13 creating avoid having a rounded shape. The inner walls of the rounded void arethreaded to accept a screw-type wedge that is described below in greaterdetail. Strongback 11 has sides 19 and 20 being similar in size, shapeand location to those of strongback 901 but without serrations at thetop of the outer edges.

[0075]FIG. 10b is a broken top view of the strongback of FIG. 10a,assembled with a hammerhead and handle according to an embodiment of thepresent invention. In this simplified view strongback 11 is shownassembled with a handle 27 and a hammerhead 25 prior to the insertion ofa wedge. Although not shown in this view, handle 27 is provided in thisembodiment having a slot similar to Slot 304 of handle 301 of FIG. 3b,extending down into handle 27 to a depth equal to the length ofstrongback 11. Hammerhead 25 is provided having serrations 29 at bothopposite ends of the eye of hammerhead 25 positioned near the top edge.The purpose of serrations 29 is to provide an improved grip between theouter edges of Sides 19 and 20 and the inner walls of the eye ofhammerhead 25 once Sides 19 and 20 have been spread outward by theinsertion of a wedge. The rounded void created by notch 13 can be seenin this view, as can the shape of sides 19 and 20.

[0076]FIG. 10c is a broken section view of the components of FIG. 10bused with a wedge-screw according to an embodiment of the presentinvention. A section view taken along line B-B of FIG 10 b shows greaterdetail of the components as assembled according to this embodiment.Screw wedge 31 is provided being similar in form to a standard threadedscrew and having a diameter slightly larger than that of the roundedvoid created by notch 13. Screw wedge 31 is inserted down in thedirection indicated into the rounded, threaded void of slot 13. Whenscrew wedge 31 is screwed down into threaded notch 13 an outward forceis created causing the sides of strongback 11 to urge outward todimension D4 against the inner walls of the eye of hammerhead 25,thereby securing the components together similarly to methods previouslydescribed, with serrations 29 enhancing the grip. Although not shown inthis view, strongback 11 can be secured to handle 27 using variousfasteners such as previously described.

[0077]FIG. 11a is a side view of a securing wedge according to anotheralternative embodiment of the present convention. Wedge 35 is providedhaving a notch 37 similar in size and shape to n903 of strongback 901 ofFIG. 9a. Serrations 39, provided as a means for improving the gripbetween the assembled and secured components, are positioned at bothopposite edges of wedge 35.

[0078]FIG. 11b is a broken top view of the securing wedge of FIG. 11a,assembled with a hammer handle, head and strongback system according toan embodiment of the present invention. In this simplified view wedge 35is shown assembled with a handle 41 and a hammerhead 723 prior to theinsertion of a wedge. Although not shown in this view, handle 41 has aslot extending down into handle 41 to a depth equal to the verticalheight of wedge 35. Metal plates 45 and 46 are provided in thisembodiment being similar in size and shape to plates 703 and 704 of FIG.7a and are assembled with handle 41 similarly.

[0079]FIG. 11c is a broken section view of the assembled components ofFIG. 11b with a securing wedge and fastener according to an embodimentof the present invention. A section view taken along line C-C of FIG.11b shows greater detail of the components as assembled according tothis embodiment. Wedge 47 is provided being similar in size and shape towedge 918 of FIG. 9 c, having a width slightly greater than the openingof notch 37. Wedge 47 is inserted down in the direction indicated intonotch 37 of wedge 35, spreading this serrated sides outward to dimensionD4, thereby securing the components together similarly to methodspreviously described, with serrations 39 enhancing the grip. In thisembodiment plates 45 and 46 are secured to handle 41 using a fastener706 previously described, but the type of fastener used can vary greatlyin other alternative environments.

[0080] It will be apparent to a worker of ordinary skill that there aremany alterations that may be made in the embodiments described hereinwithout departing from the overall spirit and scope of the presentinvention. For these reasons the invention should be afforded thebroadest possible scope limited only by the claims that follow.

What is claimed is:
 1. For a striking tool having a plane of substantialsymmetry and a head with an eye for engaging a portion of a handle, amethod for securing the handle to the head, comprising the steps of: (a)slotting the portion of the handle that extends into the eye of the headin the plane of substantial symmetry, providing a slot with a firstwidth; (b) engaging a metal strongback unit in the slot, the strongbackunit having a web with a thickness substantially the width of the slot;(c) engaging the handle and strongback assembly into the eye, and (d)spreading the web of the strongback unit until metal of the strongbackunit urges against an inside surface of the head in the eye.
 2. Themethod of claim 1, wherein the web has at least one opening at an upperedge for a spreading wedge, and the web is spread in assembly by drivinga wedge into the handle and the opening in the web.
 3. The method ofclaim 1 wherein, in step (b), the strongback unit comprises sideelements having a second width greater than the web width, such that theside elements lie along opposite sides of the handle with the strongbackunit engaged in the handle slot.
 4. The method of claim 3 wherein, instep (d), spreading the web urges the side elements against the insidesurface of the head in the eye.
 5. The method of claim 3 wherein theside elements are shaped to fit a curvature of the inside surface of thehead in the eye.
 6. The method of claim 3 wherein the handle is formedon opposite sides of the slotted portion to accommodate the sideelements of the strongback unit.
 7. The method of claim 3 wherein theslot extends further along a length of the handle than the portion ofthe handle that extends into the eye of the head, and the strongbackunit fills the slot, such that the side elements, with the handle andstrongback engaged, provide an overstrike surface along a portion of thehandle length below the head.
 8. The method of claim 7 wherein thehandle is formed along opposite sides along the slot edges toaccommodate the side elements.
 9. The method of claim 1 wherein thestrongback unit has a first web in an upper portion having a lengthequal to the handle portion extending into the eye, and a second web ina lower portion, the second web formed at a right angle to the firstweb, and wherein the handle is slotted with first and second slots atright angles to accommodate both webs.
 10. The method of claim 9 whereinthe second web comprises threaded holes, and an overstrike plate isassembled to the handle below the head on the side of the handle towarda striking surface of the head, the overstrike plate secured to thehandle by fasteners extending through holes in the plate and the handle,and engaging the threaded holes in the lower web.
 11. A striking toolhaving a plane of substantial symmetry, comprising: a head with an eyefor engaging a portion of a handle; a handle with a slot of a firstwidth in the plane of substantial symmetry along a length of the portionof the handle extending into the eye; a metal strongback unit in theslot, the strongback unit having a web with a thickness substantiallythe width of the slot; characterized in that the strongback unit isspread in the eye, urging metal of the strongback unit against insidesurface of the head in the eye, to secure the head on the handle. 12.The striking tool of claim 11 wherein the web has at least one openingat an upper edge for a spreading wedge, and the web is spread inassembly by driving a wedge into the handle and the opening in the web.13. The striking tool of claim 1 wherein the strongback unit comprisesside elements having a second width greater than the web width, suchthat the side elements lie along opposite sides of the handle with thestrongback unit engaged in the handle slot.
 14. The striking tool ofclaim 13 wherein spreading the web urges the side elements against theinside surface of the head in the eye.
 15. The method of claim 3 whereinthe side elements are shaped to fit a curvature of the inside surface ofthe head in the eye.
 16. The striking tool of claim 13 wherein thehandle is formed on opposite sides of the slotted portion to accommodatethe side elements of the strongback unit.
 17. The striking tool of claim13 wherein the slot extends further along a length of the handle thanthe portion of the handle that extends into the eye of the head, and thestrongback unit fills the slot, such that the side elements, with thehandle and strongback engaged, provide an overstrike surface along aportion of the handle length below the head.
 18. The striking tool ofclaim 17 wherein the handle is formed along opposite sides along theslot edges to accommodate the side elements.
 19. The striking tool ofclaim 11 wherein the strongback unit has a first web in an upper portionhaving a length equal to the handle portion extending into the eye, anda second web in a lower portion, the second web formed at a right angleto the first web, and wherein the handle is slotted with first andsecond slots at right angles to accommodate both webs.
 20. The strikingof claim 19 wherein the second web comprises threaded holes, and anoverstrike plate is assembled to the handle below the head on the sideof the handle toward a striking surface of the head, the overstrikeplate secured to the handle by fasteners extending through holes in theplate and the handle, and engaging the threaded holes in the lower web.